Re: Changes to Events API

Hi Martin,

thanks for proposal. I will use it in XML case. I have just one 
question, do you consider a *cycles*? It is not problem of XML model, 
but in general it is possible, isn't it?

Thanks,
Libor


Martin Matula wrote:
> Hi,
> from the discussions that I saw at some external mailing lists and from 
> the discussions I had with the people here at Sun that intend to use the 
>  MDR it showed up that what would be a good thing to have is a 
> possibility to listen to events on objects' containers (composites). 
> This means that the events should be propagated not only up to the 
> proxies, but also to objects' composites. This way someone who wants to 
> listen to any changes in a Java class would listen to the class only 
> (and would not be forced to register listeners to all the methods, their 
> parameters, attributes, etc.) The same is applicable in many other cases 
> (UML metamodel, XML, etc.)
> Thus I propose that events on RefObjects are propagated also to their 
> composites. Once the event gets to the composite, it will be propagated 
> to its composite, but not to its proxies (thus the current event path 
> via proxies would be followed only for events originating from the given 
> RefObject). I.e.:
> 
> APackage extent contains AClass and BClass class proxies, A is instance 
> for AClass, B is instance for BClass.
> A is a component of B, A is changed -> event goes to A, from A to AClass 
> and B, at B it is forgoten, from AClass it goes to APackage, from 
> APackage it goes to repository.
> 
> Now the question is, how the listeners should register for the events 
> from containers. I would like to add method addListener(..., boolean 
> includeComponents), however this would be applicable only for 
> registering listeners on RefObjects. Should there be a special 
> RefObjectEventSource for RefObjects? Any suggestions are welcome.
> Martin
> 

-- 
Libor Kramolis, Software Engineer      | <[email protected]>
NetBeans/Sun Microsystems, XML Project | http://xml.netbeans.org/